掲載雑誌（和）：
岩盤力学に関するシンポジウム講演論文集
Vol：
18巻
年：
1986年
頁：
156-160頁
著者（和）：
山本 卓也，岩野 政浩，里 優， 亀村 勝美
タイトル（和）：
弾性波速度を用いた岩盤不連続面の方向分布の評価
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抄録（和）：
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キーワード（和）：
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掲載雑誌（英）：
PROCEEDINGS OF THE SYMPOSIUM ON ROCK MECHANICS
著者（英）：
takuya yamamoto,masahiro iwano,masaru sato,katsumi kamemura
タイトル（英）：
THE ESTIMATION OF CRACK DISTRIBUTION BY MEANS OF ELASTIC WAVE
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抄録（英）：
Seismic survey has been one of the important technique to detect the faults and geological status of the fround. And the velocity of elastic wave is used as the index for rock mass classification. Recently, the relationship between the time lag of elastic wave and mechanical property of rock mass is studied experimentally. In this paper, the fundamental correlation between the behavior of elastic wave propagation and the characteristics of cracks is clarigied and then methodology of transformation from time lag function to density function of cracks. There exist two types of elastic wave gose through open cracks, the velocity of elastic wve decreases because of the wave propagation evading crack. On the other hand, the velocity of elastic wave across intact cracks delays caccording to the property of filling material, for example clay or water. In the latter case, the relationship between then time log of elastic wave T(m) and the density function E(n,r,t) of cracks is given s below. Where, T(m): the time lag data per unit length of m-direction san line, :the density of cracks, E(n,r,t):the density funciton of cracks with normal vector n, diameter r and time lag t. Conclusions are summarized as follows.(1) The numerical technique of transformation from T(m) to E(n,r,t) is clearly described.(2) The second rank tensor of E(n,r,t) shows good accordance with the given distribution of ctacks on the following conditions:i) ctack is idealized as diskii) linearlity rule between time lag of elastic wave and the number of cracks is giveniii) normal stiffness Kn and shear stiffness Ks of a crack are both high value iv) discontinuous rock is precisely surveyed with elastic wave(3) The time lag function dose not always reflect the dstribution of cracks because the width, stiffness and time lag of cracks are evaluated as constant.
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キーワード（英）：
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記事区分：
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委員会論文集